1. Field of the Invention
The present invention relates to a heat exchanger, which is installed in a vehicular air conditioning apparatus that performs temperature adjustment of a vehicle compartment, whereby the heat exchanger is used by the vehicular air conditioning apparatus for cooling and heating air that is blown into the vehicle compartment. The present invention also concerns a partitioning method for such a heat exchanger, for forming a partition member that partitions the interior of the heat exchanger.
2. Description of the Related Art
In a vehicular air conditioning apparatus that is mounted in a vehicle, for example, it is known to provide a first blower for the purpose of taking in air from the vehicle compartment into the casing, and a second blower for the purpose of taking in internal and external air with respect to the vehicle into the casing. In such a vehicular air conditioning apparatus, air that is introduced from an internal air introduction port by rotation of the first blower is heated by a first heat exchanger and then is blown into the vehicle compartment through a first air passage from the face blow-out port or the foot blow-out port. In addition, air that is introduced from an external air introduction port by rotation of the second blower is heated by a second heat exchanger and then is blown into the vehicle compartment through a second air passage from the defroster blow-out port.
With the aforementioned vehicular air conditioning apparatus, for example, as disclosed in Japanese Laid-Open Patent Publication No. 09-104216, respective partitioning plates are provided on upstream and downstream sides of the heat exchanger, which correspond respectively to ventilation passages therein. By means of the partition plates, one of such ventilation passages and the other of such ventilation passages are separated (partitioned) from each other. Together therewith, by arranging the partition plates on a straight line with any one of a plurality of tubes that constitute the heat exchanger, air that flows through one of the ventilation passages is separated in the heat exchanger from air that flows through the other of the ventilation passages.
However, using the aforementioned technique, for example, in the case that the technique is applied to a heat exchanger having two layers of tubes, within the heat exchanger, air still passes and flows between one set of the tubes, which are arranged on a front surface side, and the other set of tubes, which are arranged on the rear surface side of the heat exchanger.
Consequently, with a heat exchanger having such a two-layered arrangement of tubes, air which flows through one or the other of the ventilation passages and flows into the heat exchanger tends to flow from a passage in which the air flow rate is abundant, and which is high in pressure, toward the side of a passage in which the air flow rate is smaller and which has a relatively low pressure. As a result, the air inside each of the passages on the downstream side of the heat exchanger does not obtain desired airflow rates, so that ultimately, the mixing ratio between cool air and warm air becomes altered. Also, the air, which is blown out from each of the blow-out ports inside the vehicle compartment, is not capable of achieving a desired temperature and blowing rate.
Further, in the case that the ventilation passages are divided by the aforementioned partition plate into first and second individual ventilation passages, for example, in the interior of the heat exchanger, air that passes through small gaps between the partition plate and the tubes tends to leak out to the ventilation passage on the other side. Thus, there has been a demand to carry out blowing of air into the vehicle compartment at desired flow rates, by reliably suppressing the occurrence of such air leakage.